It is well known to form manufactured articles within a forming tool or that includes a first forming tool and a second forming tool that define a cavity there between in the shape of the finished article. The forming tools are typically mounted in a press with one forming tool being stationary and the other forming tool being movable between a closed position in which the forming tool cavity is defined and an open position so that the finished article can be removed from the forming tool. Many types of forming processes are known. For example the finished article may be molded of a fluid plastic material that is injected or blown or vacuumed into the forming tool, or molded of a sheet of plastic material that is compressed or blown or vacuumed into the forming tool. Or the finished article may be formed of a sheet of preheated metal that is blown or vacuumed into the forming tool.
It is the norm in the design of formed articles to design the article so that the forming tool that is used to form the article will have forming tool walls that extend at a positive draft angle that ensure ease of removal of the finished article from the forming tool. However, in many instances this would compromise the desired shape of the finished formed article and it is therefore necessary to design the formed article with more complex shapes that require that the forming tool have a negative draft angle by undercutting a wall of the forming tool cavity. In this case the finished article is locked within the forming tool and cannot be removed. Thus it is known to mount a segment of the forming tool on a slide mechanism so that after the article is formed, the wall segment of the forming tool can be linearly withdrawn away from the formed article to unlock the formed article for removal from the cavity.